As a conventional technology of this type, a stereoscopic video receiver has been known in which a left-eye screen and a right-eye screen shot by a stereo camera are displayed on a small-sized display to form a stereoscopic video, the stereoscopic video is generated so that it can be viewed so as to have a size equivalent to the size of a video displayed on a large-sized display (for example, refer to Japanese Unexamined Patent Application Publication No. 2009-17207).
In the stereoscopic video receiver described above, the stereoscopic video is present on a virtual display D0 as depicted in FIG. 5, and is formed by separately viewing the left-eye screen and the right-eye screen displayed on a display of a television, a personal computer, or the like having a width dimension shorter than that of the virtual display D0 by using left and right eyes. A distance between a left image and a right image of an infinite distance subject image, that is, a distance between left and right corresponding points of the infinite distance subject image, is adjusted so as to have a distance equal to a distance between left and right pupils of a viewer, that is, an interpupillary distance.
When the left-eye screen and the right-eye screen displayed on the display are viewed, it is normally desired to view the screens a distance (a recommended viewing distance Dr) thirty times to fifty times as long as an interpupillary distance BS of a viewer away from the virtual display D0. In particular, when moving pictures are viewed, it is desired to set the distance forty times as long as the interpupillary distance BS of the viewer. For example, an average value of interpupillary distances BS (58 mm to 72 mm) of viewers is set at approximately 65 mm, the recommended viewing distance is approximately 2500 mm. Also, while a screen width W0 of the virtual display D0 can be freely set to some extent, if the screen width W0 is extremely narrow, a powerful impression at the time of viewing is lost, and therefore a screen width on the order of 1800 mm is required.
When the screen video on the virtual display D0 as depicted in FIG. 5 is displayed on a display D1 formed with a width dimension W1 narrower than that of the virtual display W0 as depicted in FIG. 6, the width dimensions of a left-eye screen DL and a right-eye screen DR are reduced according to a ratio in width dimension between the display D1 and the virtual display D0, and therefore a distance J between left and right corresponding points PL and PR of an infinite distance subject image P is also reduced. For example, when the virtual display D0 having a width of 1800 mm is represented by the display D1 having a width of 345 mm, if the interpupillary distance BS of the viewer is set at 58 mm, the distance J between the left and right corresponding points PL and PR of the infinite distance subject image P is 345/1800×58=11.12 mm, which is shorter than the lower limit of the interpupillary distance BS of a general viewer, that is, 58 mm.
An observation distance L of the display D1 as depicted in FIG. 6 is 2500×345/1800=approximately 479 mm. When a viewer having an interpupillary distance of 58 mm tries to view the infinite distance subject image P via this display D1, a depth N of the stereoscopic video is merely 479/((58/11.12)−1)=113.5 mm on the display D1 of 15.5 inches. That is, the depth is merely 113.5 mm away from the display D1 even for a furthest subject, other subjects are viewed toward the front, and therefore only a stereoscopic video with a less sense of stereoscopy may be disadvantageously obtained.
In the display disclosed in the patent gazette described above, to mitigate this problem and provide a sense of stereoscopy to the stereoscopic video, the left-eye screen and the right-eye screen are displayed so as to be significantly displaced in a direction of separating these screens away from each other in the display having a limited width dimension to enlarge the distance between the left and right corresponding points of the infinite distance subject image so that this distance is equal to the interpupillary distance of the viewer. With this, the left-eye screen and the right-eye screen are superposed on each other with respect to the width dimension of the display to decrease an area where the screens are to be actually displayed. This may disadvantageously deprive the stereoscopic video of a powerful impression.
To address the problem, there is a need to develop a stereoscopic video with a sense of stereoscopy and a powerful impression even when the left-eye screen and the right-eye screen are displayed on a small-sized display. An object of the present invention is to solve this problem.